I've no idea even what KINGDOM this thing I found on the beach here in SE Brazil belongs to. My local friend said ppl here think it's mollusc eggs, but I don't think so.
https://www.inaturalist.org/observations/279923349
https://www.inaturalist.org/observations/279923349
Comments
They are vaguely similar to corals but without the hard excretion (not closely related though)